Definitely not a West Coast thing. I have one nephew who will only eat a carrot or a cucumber if it is dipped in ranch dressing. And another relative who dips fries, vegatables and chicken tenders in ranch dressing. On a recent vacation with extended family from Boston, Virginia and the Mid WEst, we prepared a crudite plate each night for the kids before dinner, and i'll bet we used gallons and gallons of the stuff. I presonally don'tunderstand it, as I don't really care for it- but it seems to be popular with the children.

The original recipe was developed at the Hidden Valley Guest Ranch in California. The commercial product named after it was developed in the labs at Clorox, which is headquartered in Oakland, California, but I believe the brand was introduced nationally. Just plain "ranch" is now a generic name for any buttermilk dressing. Malcolm Gladwell in the New Yorker came up with a slightly different version of the story than that in the Slate article referenced above:

"The couple who owned Hidden Valley Ranch, near Santa Barbara, had come up with a seasoning blend of salt, pepper, onion, garlic, and parsley flakes that was mixed with equal parts mayonnaise and buttermilk to make what was, by all accounts, an extraordinary dressing. Clorox tried to bottle it, but found that the buttermilk could not coexist, over any period of time, with the mayonnaise. The way to fix the problem, and preserve the texture, was to make the combination more acidic. But when you increased the acidity you ruined the flavor. Clorox's food engineers worked on Hidden Valley Ranch dressing for close to a decade. They tried different kinds of processing and stability control and endless cycles of consumer testing before they gave up and simply came out with a high-acid Hidden Valley Ranch dressing — which promptly became a runaway best-seller. Why? Because consumers had never tasted real Hidden Valley Ranch dressing, and as a result had no way of knowing that what they were eating was inferior to the original. For those in the food business, the lesson was unforgettable: if something was new, it didn't have to be perfect."

I was just to about to say... what Ranch Dressing craze... in California I rarely see it on anything menus except as an option with Green Salads.

Anyway... my guess is that it has to do with the American cooking paradox.... with everyday that passes more Americans are into Gourmet foods & cooking... but with everyday that passes Home Cooking... particularly from scratch... becomes a lost art in this country. (Generation Y'ers stastically can barely boil water). I guess Ranch Dressing is an easy way to change things up for people that don't know how to cook from scratch.

There was a decent article in Slate called America's Love Affair With Ranch Dressing. It talks about the history of Ranch Dressing and how it has grown in popularity. It was invented at Hidden Valley Ranch.